I am having a hell of a job trying to get a delegate setup on a custom view.
This is the init code:
- (id)initWithPageNumber:(int)page {
self = [super init];
if (self) {
UpgradeContentView *v = [[UpgradeContentView alloc] initWithPageNumber:page];
[self setView:v];
[v release];
}
return self;
}
then in viewDidLoad I have this:
- (void)viewDidLoad {
[super viewDidLoad];
[(UpgradeContentView *)self.view setDelegate:self];
}
which does not error and the program runs, but none of my delegate methods get called, I have placed NSLog calls and break points but the delegate seems not to be working.
I am doing this completely wrong?
Thanks
Related
When I call loadNibNamed: in init, the UIViewController can't receive viewDidLoad event.
But if I put call to loadNibNamed: somewhere else, it works fine. What is the reason?
-(id)init
{
self=[super init];
if(self){
[[NSBundle mainBundle]loadNibNamed:#"MainView" owner:self options:nil];
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
}
This is because when you are writing implementation of init , you are not calling super with nib name correctly.
-(id)init {
self = [super initWithNibName:#"MainView" bundle:nil];
return self;
}
I have this cascade :
Somewhere in the app
- (void) go
{
MyCustomViewController* controller = [[MyCustomViewController alloc] init];
controller.delegate = self;
[controller run];
}
in MyCustomViewController
- (id) init
{
// there is an if statement here in real to choose another XIB if needed
// but I only display here the code that is called in my tests
self = [super initWithNibName:#"MyXIB" bundle:nil];
if (!self) return nil;
self.delegate = nil;
return self;
}
- (void) run
{
// do things with self.view
}
MyCustomViewController inherits GenericWindowController
in GenericWindowController
/*- (id) initWithNibName:(NSString*)nibNameOrNil bundle:(NSBundle*)nibBundleOrNil
{
if (!(self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil])) return nil;
self.view.userInteractionEnabled = NO; // THE APP CRASHES HERE ! self.view is nil
...
return self;
}*/
// METHOD created following first answers : NOT CALLED
- (void) viewDidLoad
{
self.view.userInteractionEnabled = NO;
// and many other things done with self.view
}
MyXIB has its File's owner set to MyCustomViewController and the view is connected.
All files are included and checked into the project.
GenericWindowController is designed to make some standard stuff.
MyCustomViewController extends this stuff to work with a custom View, as designed in MyXIB.
Why self.view is nil in GenericWindowController ?
Why viewDidLoad is not called ?
A view controller should not try to access its view in initWithNibName:bundle:. It should wait until viewDidLoad.
self.view is only valid after viewDidLoad -- in init... it is still nil.
Incredible !!! The problem was because of a missing localization for the XIB. Added the localization, and no problem anymore.
I am trying to push an opengl UIView to my navigation controller like this
GraphViewController *gvc = [[GraphViewController alloc] initWithTicker:[listOfItems objectAtIndex:indexPath.row]];
[self.navigationController pushViewController:gvc animated:YES];
[gvc release];
The initWithTicker method looks like this
-(id) initWithTicker:(NSString*)ticker{
self = [super initWithNibName:nil bundle:nil];
if (self) {
self.title = ticker;
EAGLView *eagl = [[EAGLView alloc] initWithFrame:[UIScreen mainScreen].bounds];
eagl.animationInterval = 1.0 / 60.0;
[eagl startAnimation];
self.view = eagl;
}
return self;
}
When I go back and forward in my UINavigationController, the drawView method (in EAGLView) keeps looping. Furthermore, if I pushViewController again, the first one does not stop and a new one is created! I've tried making this an instance variable so only one is created and it has the same effect. I would be grateful if anyone has insight as to why this is happening
sergio Suggestion:
-(id) initWithTicker:(NSString*)ticker{
self = [super initWithNibName:nil bundle:nil];
if (self) {
self.title = ticker;
}
return self;
}
// Implement loadView to create a view hierarchy programmatically, without using a nib.
- (void)loadView {
eagl = [[EAGLView alloc] initWithFrame:[UIScreen mainScreen].bounds];
self.view = eagl;
}
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
eagl.animationInterval = 1.0 / 60.0;
[eagl startAnimation];
[super viewDidLoad];
}
same behaviour.
---This is how I fixed my drawView looping problem--
-(void)viewDidAppear:(BOOL)animated {
[eagl startAnimation];
[super viewDidAppear:animated];
}
-(void)viewDidDisappear:(BOOL)animated {
[eagl stopAnimation];
[super viewDidDisappear:animated];
}
--Craigs solution --
if(graphView == nil){
graphView = [[GraphViewController alloc] initWithTicker:[listOfItems objectAtIndex:indexPath.row]];
}else{
[graphView release];
graphView = [[GraphViewController alloc] initWithTicker:[listOfItems objectAtIndex:indexPath.row]];
}
Are you creating a new GraphViewController every time you want to push one onto your navigation stack? If so, it doesn't really matter how you're handling the creation of your EAGLView instance variable, since you're never going to be interacting with that view controller again anyway.
For example:
User taps something, a new GraphViewController is pushed on the stack
User goes back, this view controller continues to run
Return to 1. and repeat (thus creating a SECOND GraphViewController, and then a third, and then a fourth... etc.)
What you should probably be doing is maintaining your GraphViewController as an instance variable, and only creating it once. This will ensure that you're in turn only creating one EAGLView.
if (_graphViewController == nil) {
_graphViewController = [[GraphViewController alloc] initWithTicker:[listOfItems objectAtIndex:indexPath.row]];
}
[self.navigationController pushViewController:_graphViewController animated:YES];
Then, be sure to release the view controller in your dealloc method if you're going to be maintaining it as an ivar.
Would you try executing this code of yours:
EAGLView *eagl = [[EAGLView alloc] initWithFrame:[UIScreen mainScreen].bounds];
eagl.animationInterval = 1.0 / 60.0;
[eagl startAnimation];
self.view = eagl;
inside of loadView? I am not sure about why your view is behaving like you say, but that is the place where you are supposed to build your UI... so it might make a difference...
Furthermore, I would call [eagl startAnimation]; only in viewDidLoad...
Hope it helps...
I am trying to implement AQGridView based upon the ImageDemo in the /examples folder. I have a view controller with the following declaration:
#interface ImageDemoViewController : UIViewController <AQGridViewDelegate, AQGridViewDataSource, ImageDemoCellChooserDelegate>
{
...
None of the datasource methods in my view controller such as
- (NSUInteger) numberOfItemsInGridView: (AQGridView *) aGridView
{
return ( [images count] );
}
are being called. Here is where I setup the gridview making my view controller the delegate for the gridview.
- (void)viewDidLoad
{
[super viewDidLoad];
self.gridView.autoresizingMask = UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight;
self.gridView.autoresizesSubviews = YES;
self.gridView.delegate = self;
self.gridView.dataSource = self;
images=[[NSMutableArray alloc]init];
[images addObject:#"http://t3.gstatic.com/images?q=tbn:ANd9GcTOXAzFMoK441mcn9V0OemVe_dtAuCpGjBkLrv4rffyOjYIo45BEw"];
[self.gridView reloadData];
}
If I set a breakpoint on
[self.gridView reloadData];
the line is executed but reloadData method in AQGridView is not called. The only difference from the ImageDemo is I do not have a .xib file for the view controller. Have I forgotten to hook up something, resulting in the datasource methods not being called?
If there's no XIB, then who's creating the gridView? If it's never created, then it would be NIL, and you'd have the behavior you describe. (If that's it, then just adding:
self.gridview = [AQGridView alloc] initWithFrame: ...]; should suffice.
Had the same problem. Solved by replacing the view with the AQGridView.
[self.view addSubview:self.gridView]
self.view = self.gridView;
Full method:
- (void) viewDidLoad
{
[super viewDidLoad];
self.gridView = [[AQGridView alloc] init];
self.gridView.autoresizingMask = UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight;
self.gridView.autoresizesSubviews = YES;
self.gridView.delegate = self;
self.gridView.dataSource = self;
self.view = self.gridView;
[self.gridView reloadData];
}
Maybe you could try implementing this:
- (void)LoadSearch
{
NSURL *test1 = [NSURL URLWithString:#"http://www.4ddraws.com/search_iphone.asp"];
NSURLRequest *test = [NSURLRequest requestWithURL:test1];
[web4D setScalesPageToFit:(YES)];
[web4D loadRequest:test];
}
I have a UITabbBarController with a UITableView. Under certain circumstances the TabBarControllers dataset requires updating when a user arrives from another view,
e.g. the initial load when the TabBarController is called the first time, or when the settings are changed.
This dataset update takes about 2 seconds and I want to show an UIActivityIndicatorView.
Trouble is that when I enter from another view I don't know which view to attach it to, since the loading of the tabbarController is carried out in the viewWillAppear method.
Any clues how I can go about this?
I've done this sort of thing in the viewDidAppear method. My code kicks off a background task to load the data from a url. It also hands the background task a selector of a method to call on the controller when it is done. That way the controller is notified that the data has been downloaded and can refresh.
I don't know if this is the best way to do this, but so far it's working fine for me :-)
To give some more details, in addition to the selector of the method to call when the background task has loaded the data, I also and it a selector of a method on the controller which does the loading. That way the background task manages whats going on, but the view controller provides the data specific code.
Here's there viewDidAppear code:
- (void) viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
if (reloadData) {
BackgroundTask *task = [[BackgroundTask alloc] initWithMethod:#selector(loadData) onObject:self];
task.superView = self.view.superview;
task.notifyWhenFinishedMethod = #selector(loadFinished);
[task start];
[task release];
}
}
The background task has an optional superView because it will add a new UIView to it containing an activity indicator.
BackgroundTask.m looks like this:
#implementation BackgroundTask
#synthesize superView;
#synthesize longRunningMethod;
#synthesize notifyWhenFinishedMethod;
#synthesize obj;
- (BackgroundTask *) initWithMethod:(SEL)aLongRunningMethod onObject:(id)aObj {
self = [super init];
if (self != nil) {
self.longRunningMethod = aLongRunningMethod;
self.obj = aObj;
}
return self;
}
- (void) start {
// Fire into the background.
NSThread *thread = [[NSThread alloc] initWithTarget:self selector:#selector(execute:)object:nil];
thread.name = #"BackgroundTask thread";
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(taskFinished:) name:NSThreadWillExitNotification object:thread];
[thread start];
[thread release];
}
- (void) execute:(id)anObject {
// New thread = new pool.
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
if (self.superView != nil) {
busyIndicatorView = [[BusyIndicator alloc] initWithSuperview:self.superView];
[busyIndicatorView performSelectorOnMainThread:#selector(addToSuperView)withObject:nil waitUntilDone:YES];
}
// Do the work on this thread.
[self.obj performSelector:self.longRunningMethod];
if (self.superView != nil) {
[busyIndicatorView performSelectorOnMainThread:#selector(removeFromSuperView)withObject:nil waitUntilDone:YES];
}
[pool release];
}
- (void) taskFinished:(NSNotification *)notification {
[[NSNotificationCenter defaultCenter] removeObserver:self name:NSThreadWillExitNotification object:notification.object];
[self performSelectorOnMainThread:#selector(notifyObject)withObject:nil waitUntilDone:NO];
}
- (void) notifyObject {
// Tell the main thread we are done.
if (self.notifyWhenFinishedMethod != nil) {
[self.obj performSelectorOnMainThread:self.notifyWhenFinishedMethod withObject:nil waitUntilDone:NO];
}
}
- (void) dealloc {
self.notifyWhenFinishedMethod = nil;
self.superView = nil;
self.longRunningMethod = nil;
self.obj = nil;
[super dealloc];
}
#end
Finally as I said I put up a activity indicator. I have a xib which contains a 50% transparent blue background with an activity indicator in the middle. There is a controller for it which has this code:
#implementation BusyIndicator
#synthesize superView;
#synthesize busy;
- (BusyIndicator *) initWithSuperview:(UIView *)aSuperView {
self = [super initWithNibName:#"BusyIndicator" bundle:nil];
if (self != nil) {
self.superView = aSuperView;
}
return self;
}
- (void) addToSuperView {
// Adjust view size to match the superview.
[self.superView addSubview:self.view];
self.view.frame = CGRectMake(0,0, self.superView.frame.size.width, self.superView.frame.size.height);
//Set position of the indicator to the middle of the screen.
int top = (int)(self.view.frame.size.height - self.busy.frame.size.height) / 2;
self.busy.frame = CGRectMake(self.busy.frame.origin.x, top, self.busy.frame.size.width, self.busy.frame.size.height);
[self.busy startAnimating];
}
- (void) removeFromSuperView {
[self.busy stopAnimating];
[self.view removeFromSuperview];
}
- (void) dealloc {
self.superView = nil;
[super dealloc];
}
#end
Hoep this helps.